I write this thread because my backlight control auf my DELL Vostro 3700 doesn't work like it should do.

I can control it with the hardware keys FN+Up/Down... but this was most time a litte bit buggy - sometimes I have to set the backlight to the lowest value and than when I scale it up again its reacting first time or it react right (to make it complete bright)

But now I found, that I have to set

Code:

Option "RegistryDwords" "EnableBrightnessControl=1"

in Xorg.conf section of the driver, which I also did.

The main problem is, that I can not control the brightness per software with as example: